Metal fastener



March 14, 1961 LlDSKY 2,974,378

METAL FASTENER Filed Jan. 3, 1957 INVENTOIQ.

Jlklma Lids? BY .A, fl W/ A TTORNE Y METAL FASTENER .liiliiis Lidsky, Beach, Fla., assignor to Ronel Corporation, a corporation of Florida Filed Jan. 3, i953, Ser. No. 632,349

The present invention relates to metal fasteners and more particularly to metal fasteners of the type in which a plurality of prongs surround an opening in a sheet, strip or plate and project therefrom in a direction at right angles to the same. These prongs are integral with the sheet, strip or plate from which they project and are normally formed by slitting the sheet andbending the slot portions away from the sheet to form the projecting prongs.

In accordance with the present invention, the sheet is formed with intersecting slits and openings are severed in the sheet at the opposite ends of the slits. The sheet is then bent about a straight or preferably a curved line joining the said openings to thereby produce, surrounding a large opening in the sheet, a plurality of spaced apart prongs which are barbed or arrow-shaped and which possess as a result of this barbed configuration, an en- 2,974,378 Patented Mar. 14, 1961 openings 14. These openings 14 are spaced apart from hanced ability to remain firmly embedded in a wood or other base into which the pronged strip is driven.

As will be understood, each individual sheet, strip or plate may have one or a plurality of large openings with prongs projecting therearound and these prongs project at approximately right angles from the sheet at one side of the sheet or from both sides of the sheet.

In accordance with preferred practice of the invention, each prong is formed with an arcuate cross-section throughout its length to provide enhanced dimensional stability to the prongs and to thereby increase the resistance of the prong to buckling when the prong is driven into a base.

The invention will now be more fully described in conjunction with the accompanying drawings in which:

Fig. 1 is a plan view of a sheet, strip or plate indicating diagrammatically the slits and openings which are to be cut therethrough in accordance with the invention;

Fig. 2 is a perspective view showing the sheet, strip or plate of Fig. l'afterslitting and cutting thereof;

Fig. 3 is a perspective view showing the completed product which is formed when the product of Fig. 2 has the prong portions thereof bent out of the plane of the sheet along curved lines interconnecting the small openings shown in Fig. 2; 1

Fig. 4 is a top plan view, similar to Fig. '1 and showing a modified design in accordance with the invention for the purpose of illustrating the scope of the invention; and Fig. 5 is a perspective view formed from the blank of Fig. 4 after slitting, cutting and bending.

Referring particularly to Fig. 1, there is shown a metal strip 10 which may contain space for the production of one or several fastening areas in which prongs project from the strip surrounding a large opening in the strip.

Shown on the strip 10 are slit lines 11 and 12 which intersect one another. It will be appreciated that al- 7 though only two slit lines are shown in the form of the invention which is illustrated, that more than two intersecting slit lines could be employed.

At the extremities of each of the slit lines 11 and 12 is shown lines 13 which are cut lines which circumscribe one another and from the intersection of the slit lines 11 and 12, said intersection being here identified by the numeral 15'.

Referring to Fig. 2, the strip is shown after slitting on the lines 11 and 12 and after cutting on the lines 14. In this figure of the drawing, the opening 14 can be seen with particular clarity.

There is shown in both Figs. 1 and 2 dotted lines 16 which arcuately interconnect the openings 14. The dotted lines 16 are bend lines and in the form of the invention illustrated in Figs. 1-3, the bend lines 16 define a circle. This is preferred practice of the invention and the bend need not be arcuate since it.could Well be straight and, if arcuate, the combined arcs need not form a circle but could form any closed pattern whether regular, as an ellipse, or not; I

It will be appreciated that the slits 11 and 12 and the cuts 13 can be made in any order. It is preferred, for practical purposes, to simultaneously form the slits 11. and 12 and the cuts 13. It is stressed that the sequence of operations forms no part of the invention.

The completed metal fastener, after bending along the lines 16 in Fig. 2 is depicted in Fig. 3 where it can be seen that two fastening areas, indicated generally by the numeral 17, have been formed in the strip 10. It will furtherbeen seen that each fastening area 17 is constituted by spaced apart prongs 18 which surround and partially define large openings 19 in the strip 10. Of greatest importance is the fact that each of the prongs 18 possesses a pointed forward portion '20 and a narrowed intermediate portion 21 which define between them a barbed portion 22.

The bending operation which transforms the slit and cut product or blank of Fig. 2 into the finished metal fastener of Fig. 3 can be simply effected by passing a cylindrical tool through the strip 10. Desirably, the strip 10 is supported on a die having a circular opening for receiving the cylindrical forming or bending tool so that a sharp and Well defined bend line 16 will be formed. It will be particularly seen that the prongs 18 shown in Fig. 3 are arcuate in cross-section. This provides increased resistance to buckling of the prongs 18 when the fastener is used.

The arcuate cross-section of the prongs 18 is uniform throughout the length thereof. The production of this uniformity of arcuateness over the length of the prongs is readily attained by forcing the cylindrical forming tool into a cylindrical recess large enough to just receive the forming tool and the prongs. V

The cylindrical forming tool and the die having a cylindrical recess are not shown in the drawing since the intended structure is conventional and does not per se form any part of the invention.

Figs. 4 and 5 are simply illustrative of various modifications in design which are included within the scope of the invention. For the purpose of simplifying discussion and to clarify the relationship between the form of the invention which is illustrated in Figs. 1-3 and the form shown in Figs. 4 and 5, the latter figures use the same identifying numerals with a prime to distinguish specific variations.

As will be evident from a review of Figs. 4 and 5, the size and shape of the openings 14, the length of the slit lines 11 and 12, the shape and disposition of the bend lines 16 can all be varied considerably. The shape of the barbs 22 is also subject to wide variation. It will be appreciated that the metal fasteners of the invention are capable of widely divergent uses and the use to which the fastener is intended to be adapted will determine the thickness of the metal strip 10 and its shape, the number of fastening areas 17 and the direction of the prongs 18.

The intended use will also dictate which of many posticular utility in the prefabrication of wooden partitions and trusses useful in the construction of homes and similar building structures.

I claim:

A fastening plate, for wooden truss structures, comprising a metal sheet, strip or plate having plural spaced fastening areas formed therein nad each including a plurality of prongs integral with said sheet and projecting substantially perpendicularly from a surface thereof, the prongs of each fastening area being uniformly positioned around the circumference of a circle embracing an opening in the sheet; at least a portion of the periphery of said opening being coincident with a corresponding portion of the circumference of said circle; the bases of the prongs forming parts of the circumference of said circle;

each of said prongs haw'ng a pointed extremity formed 2 by diverging outer edges terminating at relatively sharp barb-forming junctions with relatively inwardly converging portions of side edges of a narrower intermediate section, the side edges including portions merging smoothly with the circumference of said circle; said prongs having a transversely arcuate cross-section.

References Cited in the file of this patent UNITED STATES PATENTS 800,248 Popple Sept. 26, 1905 1,089,878 Steinhauser Mar. 10, 1914 1,297,611 Upson Mar. 18, 1919 1,599,985 Carlson Sept. 14, 1926 1,638,612 Baus Aug. 9, 1927 2,533,786 Gagnier Dec. 12, 1950 2,745,122 Green May 15, 1956 2,827,676 Sanford Mar. 25, 1958 2,844,852 -West July 29, 1958 FOREIGN PATENTS 749,142 France May 2, 1933 

